Consumer multimedia systems of today typically consists of one or more video and audio (V/A) sources communicatively coupled to one or more V/A sinks. Examples of V/A sources include DVD players, Blu-ray players, set-top boxes, camcorders, game consoles, personal computers, and others. Examples of V/A sinks include televisions, personal computers, projectors, audio devices, and others. Typically, standardized interfaces, in the form of cables, are used to communicatively couple V/A sources to V/A sinks.
One such standardized interface is the High-Definition Multimedia Interface, more often referred to simply as HDMI. An HDMI interface generally consists of two identical connectors attached to opposite ends of a cable. The cable typically includes seven (7) twisted pairs of copper wires for communicating various information. Four of the twisted wire pairs are adapted to communicate relatively high-speed data in the form of Transition Minimized Differential Signaling (TMDS). Of the four, three pairs are used for communicating video, audio, and auxiliary data, and are typically referred to as D1-D3. The other pair is used for transmitting a clock associated with the data, and is typically referred to as CLK. The speed of the high-speed data may range from 3 to 10 gigabytes per second (GPS).
The remaining three wire pairs are used for communicating relatively low-speed data, such as in the range of 100 kilobits per second (kbit/s) to 400 kbit/s. Two of such wire pairs are referred to as Display Data Channel (DDC) for providing communication between devices using a communication channel that adheres to an I2C bus specification. As an example, a V/A source may use the DDC to learn the video/audio format used by a corresponding V/A sink. One of the DDC wire pair, typically referred to as DDC DATA, is used to communicate data between the devices. The other DDC wire pair, typically referred to as DDC CLK, is used to transmit a clock associated with the data.
The remaining twisted wire pair for low-speed data is used for communicating remote control commands between the devices. Such data channel is typically referred to as Consumer Electronics Control (CEC). The CEC channel allows a user to use a single remote to control multiple devices coupled together via HDMI cables. More specifically, a unique address is assigned to the connected group of devices, which is used for sending remote control commands to the devices.
A drawback of the conventional HDMI is that length of the cable is typically limited to a relatively short distance. This is because distortion of the signal propagating through a twisted wire pair is significantly dependent on the length of the cable. At large lengths, the distortion of the signal may be so significant that the signal may not be able to be properly received by a V/A sink.
Optical communication systems use modulated optical electromagnetic energy or light to communicate information from one device to another. In such systems, one or more optical fibers are used to communicatively couple the devices. Further, at the transmission-side of such communication systems, an optical modulator is employed to modulate information in the form of an electrical signal onto optical energy. Typically, one or more vertical-cavity surface-emitting lasers (VCSELs) are used to perform the modulation. Similarly, at the reception-side of such communication systems, an optical demodulator is employed to demodulate information on the optical energy to produce an information-bearing electrical signal. Typically, one or more photo detectors (PDs) are used to perform the demodulation.
A VCSEL of an optical transmitter should be optically aligned with a corresponding optical waveguide or fiber in order for the optical signal to be efficiently coupled to the optical waveguide or optical fiber for transmission. Similarly, a PD of an optical receiver should be optically aligned with a corresponding optical waveguide or optical fiber in order to efficiently receive or detect the optical energy being received via the optical waveguide or optical fiber. Additionally, with regard to both VCSEL and PD, bias voltage needs to be provided to the devices in order for them to function.
Accordingly, there is a need for an HDMI or other data interface that is able to achieve lower signal distortion through the cable, thereby allowing the cable to be longer without significantly affecting the signals. Additionally, there is a need for such an interface to provide power as well. Further, there is a need to provide an indication power is available from either a V/A source or a V/A sink.
There is also a need for a mechanical assembly or mount to provide effective alignment of a VCSEL or PD with a corresponding optical waveguide or optical fiber, while at the same time, effectuating the necessary electrical routing for providing a bias voltage to such device.